Circuit-controller for electric engines.



H. &. J. S. LETORD. CIRCUIT CONTROLLER FDR ELECTRIC ENGINES.

(Application led Feb. 27, 1900.)

f No. 66H42. Patented Nov. I3, |900.

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No. 65|,742. Patented Nov. I3, i900. H. & J. S. LETURIJ.

CIRCUI'Il CONTROLLER FOR ELECTRIC ENGINES.

(Application filed Feb. 27, 1900.)

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Patented Nov. I3, |900.

No. s6|,742.

H.-&. s.y Liman. CIR'CUIT CONTROLLER FOR ELECTRIC ENGINES.

v (Applimioxi med Feb. 27, 1900.)

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JNITRD STATES PATENT Fri HENRI LETORD, or ORLANDO, FLORIDA, AND JOSEPH s. LRroRD, on

' KANsAS CITY, MISSOURI.

lRoulT-CONTROLLER FOR ELI-:orale ENGINEs.

SPECIFICATION forming parte of Letters Pet-enf Nt. 661,742, dated November? 13, ieoo.

Serial No. 6,735y (No irodelfi To @ZZ whom it may concern,.-

Beit known that we, HENRI LETORD, residing at Orlando, in the county of Orange and State of Florida, and JOSEPH S. LETORD, residing at Kansas City, in the county of Jackson and State of Missouri, have invented a new and useful Circuit-Controller for Electric Engines, of which the followingis a speciiication.

This invention relates to circuit-controllers for electric motors or engines, and particularly to that class of such devices as are used by dentists and surgeons, the object of the invention being to provide an improved circuit-controller for starting, stopping, reversing, and regulating the speed of Surgico-dental electrical engines.

With this object in View the invention consists in the improved construction, arrangement, and combination of appliances for the purpose of starting, stopping, reversing, and regulating the speed of a surgicO-dental electric engine by means of finger-pressure at the handpiece, all of which will be hereinafter fully described, and afterward specifically pointed out in the appended claims.

In order to enable others skilled in the art to which our invention appertains to make and use the same, we will now proceed to describe its construction and operation, reference being had to the accompanying drawings, forming part hereof, in which- Figure 1 is a perspective View of a surgicodental electric engine mounted on an adjustable bracket connected up with a circuitcontroller constructed in accordance with our invention and with an incandescent electriclight plug, the controller, local batteries, rheostat, resistance-coils, main-circuit closer, and pole-changer being boxed. Fig. '2 is a view of the rheostat or resistance-controller, partly in elevation and partly in vertical section, being shown in circuit with the main line. Fig. is a View of the same in rear elevation. Fig. 4E is a view illustratingthe handpiece atiachment,the main-circuit closer, and the pole-changer, together with a diagrammatic illustration of their connections. Fig. is a det-ail view of the contact-plate of the circuit-closer'. Fig. is a detail viewof the contact-plate of the pole-changer. Fig. G

is a rear view of the armature of the maine circuit closer. Fig. 7 is a rear view of the armature of the pole-changer. Fig. S is a diagrammatic view illustrating the main-line circuit. Fig. 9 is a detail top plan View of part ofthe armature of the rheostat or resistance-controller. Fig. 10 is a detail view in elevation of parts ofthe rheostat or resistance-controller in different positions from those illustrated in Fig. 2. Fig. 11 is a perspective View of the handpiece attachment. Fig. 12 is a perspective view of the parts of the handpiece attachment detached from each other, but in their proper relative position. Fig. 13 is a top plan View of the handpiece attachment. Fig. 14 is a Vertical sectional View of the handpiece attachment on the plane indicated by the dotted line a b c d in Fig. 13. 15 is a vertical sectional view on the plane indicated by the dotted line cfc d of Fig. 13. Fig. 1G is a horizontal sectional view of the handpiece attachment on the plane indicated by the dotted line g 7L of Figs. 14 and 15 looking downward.

Like numerals an d letters of reference mark the same parts wherever they appear in the several iigures of the drawings.

Referring to the drawings by letters and numerals, A in Fig. 1 indicates a box, which in practical operation will contain the rheostat or resistance-controller B, Figs. 2 and 3, and the main-circuit closer C,the pole-changer D, and the local batteries, (divisions F. and E,) as shown in Fig. 4, and resistance-coils F F F2, as shown in Fig. 3.

The handpiece attachment G (shown in Figs. et and 11 to 16) is a double circuit-closing device operated by the operator by the hand grasping the ordinary handpiece and for convenience of reference will be divided into divisions H and H, the division of G including that part above the dotted line't'z' in Fig. 4. being designated as division H and that part below that line in Fig. a or to the left of it in Fig. 13 division H.

I I', Fig. 1, indicate the arms of any Ordinary adjustable bracket for supporting any approved form of surgico-dental electric engine J, from which extends the usual flexible cable K, carrying at its Outer end the usual handpieco L, to which our improved TOO handpiece attachment G is detachably secured by means hereinafter described.

M indicates the usual incandescent electriclight plug, and N N any ordinary bracket for supporting the box A.

The construction of the handpiece attachment will tirst be described, referring especially to Figs. 11 to 16 and incidentally to other figures of the drawings.

17 1S indicate curved springs for clasping the handpiece L, said springs being secured to the under face of a block 19 of hard rubber or other suitable non-conducting material and connected by a metal strip 20, having a threaded opening in one end to receive a binding-screw 21. Secured to the strip 2O is a rod 22, projecting upward through and slightly above the block 19, a switch-lever 23 being pivotally mounted on its projecting end.

24 indicates a curved rod fixed in the block 19, projecting above it at 25 to serve as a contact-point for switch-lever 23, a dummy point 26 also projecting above block 19 to receive switch-lever at the opposite end of its throw when the circuit is broken. The curved rod 24 also extends to the end of block 19 and has a threaded opening to receive a bindingscrew 27. By this switch mechanism the local-battery circuit, the wires of which are secured by binding-screws 21 and 27, may be opened or closed, as hereinafter described, such switch mechanism forming division H ofthe handpiece attachment, as before set forth, and the circuit being from division E' of the local battery to operate the pole-changer D, the current passing from binding-post 21, metal strip or bar 2t), rod 22, switch-lever 23, and curved rod 24 to binding-screw 27 and to the pole-changer, as shown in Fig. 4.

28 indicates another metal strip or har passing from the front of the block 19 backward into the block, being provided with a threaded opening` in its front end to receive a bindingscrew 29 and tlattened and extended laterally at its rear end, crossing a vertical recess 30 in the block 19 and provided with an opening to receive the inner end of apush-button 3l, seated in said opening. The push-button is thicker in the middle than at either end, the upper end extending through a central opening 32 in a cover-plate 33, so as to be accessible to the lingers of the operator while holding the handpiece L. The shoulders atthe lower end of the body bear upon a spring 34, coiled around the lower end and resting on strip or bar 28, thus normally holding` the push-button on its outer position with its inner end out of contact willi the metal strip 20. By pressing upon the push-button the local-battery circuit from division E of the battery, Fig. 4, is closed to operate main-circuit closer C, the current passing from binding-post 21 through metal strip or bar 20, push-button end 30, strip or bar 2S to binding-screw 29 and main -circuit closer, as shown in Fig. 4.

The main-circuit closer, as illustrated at C on the left ol' Fig. 4, comprises two electric magnets 35 and 30, arranged at opposite sides of a suitable support and in reversed positions, and a soft-iron bar armature 37 is centrally pivoted to the support in position to be attracted at its opposite ends by the magnets. A spring 38 at each end normally holds the armature away from the magnets. Projecting through the armature on opposite sides of the center are the hard-rubber blocks 39 40, faced with platinum on one side, so as to form contact with pins 41 42, projecting through the support in the path of movement of the armature when attracted by the magnets. From the platinum faces ot' blocks 39 and 40 metal pins 43 and 44, Fig. G, project through the rear side of the armature and contact with curved plates 45 4G, Fig. 5, set in a circular plate 47, of non-conducting material, secured to the rear of the support and connected up in the main line with bindingposts 4S 49 at the top of the support. 'lhe pins 41 and 42 are connected up in the main line with binding-posts 50 5l, the posts 4S and 50 in this arrangement being marked or positive, and the posts 49 and 51 or negative. When the push-button 31 is forced into contact with bar 20, as before stated with reference to the hand piece attachment, the circuit from division E of the local battery is completed through division H' oi the handpiece attachment and the magnets and 36. The magnets being thus energized will attract the armature 37, bringing the platinum faces of the blocks 39 40 into contact with pins 41 42 and closing the mainline circuit from post 50 through pin 41, platinum of block 39, pin 44, and curved plate 4G to post 49 and from post 51 through pin 42, platinum ot' block 40, pin 43, and curved plate 45 to post 4S.

The pole-changer D (illustrated on the right of Fig. 4) is provided with magnets 35 3G, armatu re 37, springs 3S, hard-rubber blocks 39 40, pins 41 42, pins 43 44, curved contact-plates 45 4o, circular non-conducting plate 47, and binding-posts 4S 49 50 51, all arranged in the same relation as the corresponding parts of the main-circuitcloser C, the blocks 39 40 being platinum-faced on both sides to contact in one position wit-h pins 41 42 in one position and with similar pills 52 53 in the opposite position ot the armature. The posts 50 and 51 are marked -land respectively, as in the main-circuit closer; but the posts 4S and 49 are marked, respectively, d: and q2. The pin 41 is electrically connected with pin 52 and the pin 42 with pin 53, so that when the circuit trom division E' of the local battery is closed by throwing the switch-lever in division ll ot' the handpiece attachment the local current will energize magnets 35 36, which in turn will attract armature 37, causing contact of the pins 41 and 42. The main line will then be closed from post 50, pin 41, the platinum of IOO IIO

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block 39, pin 44, curved plate 46, post 49, post l, pin 42, platinum of block 40, pin 43, curved plate 45 to post 48, and the direction through the armature will be reversed, thus reversing the motor and tool.

The rheostat or resistance-controller comprises a frame consisting of a bottom or base plate or bar 53, to which is secured by screws 54 a second bar or plate forming sides 55 56 and top 57. ln this construct-ion, shown in Figs. 2 and 3, 59 59 60 60 indicate electromagnets connected up in series with the motor itself. These magnets are made in sections, with their cores teiescoping, so as to get the maximum strength of pull.

61 indicates the armature oi' both magnets, and 62 63 rods depending therefrom into cylinders 64 65, mounted on the base-plate 53 by screws 66 67 and containing' springs 68 69, bearing upward under rods 62 63, with a normal tendency to hold the armature at its uppermost position, this position being determined adjustably by stop screws 70 7l, threaded downward through the top 57 of the frame. In the center of the armature is a slot 72, in which are pivotally mounted two pawls 73 73, which are held normally in engagement by springs 74 with one of a series of grooves 75 in a'rod or plunger 76, secured at its lower end by means of a cross-bar in a closed bottom cylinder 77, mounted to slide in an outer cylinder 78, secured to the base. A plate 79, secured to the bar 76, is guided at its ends in grooves in brackets 80 80, secured to the base outside of the cylinders. Springs 8l 8i are provided in the grooves of brackets 80, under the plate 79, having a normal tendency to force the plate, plunger-rod, and cylinder 77 upward. The cylinder 78 is provided with an air-inlet pipe 82, having valve 83, Fig. 3, to regulate the inflow, and with an outlet-pipe with a valve 84 in its bottom. Projecting from the rear of plate 79 is a contact-point 85, which by reason of the raising and lowering of the plunger and plate may be brought into contact with either of the contact-pointsp,192,193, p4, orp, projecting from an upright plate 86, secured in the rear of plate 79. The contact-point 85 is on the main-line circuit, as are also points 1J and p2, the two last named being in electric connection at q, and when the point 85 is in contact with either p' mp2 the current passes through resistances F, F', and F2. When point 85 contacts with p3, the current only passes through resistances F' and F2. /Vhen 85 is in contact with p4, the current passes through only one resistance, F2, and when 85 and p5 are in cont-act no resistance is encountered. may be given to the motor, and it will be obvious that the number may be increased or diminished, as may be desired.

To accomplish the lowering et' the contactpoint 85, the circuit-closer (l is operated, cuti tor.

Thus four different speeds stated, passes through the magnetcoils, and each time this is done the armature 6l, released trom the magnets, is raised by the springs, causing the pawls 73 73 to engage in the next higher groove 75. The current being immediatelyturned on again the magnets are energized, drawing the armature down and lowering contact-point 85 one step, as from p' toppi to p3, dac., as the case may be. The points p and p2 being electrically connected the tirs't step (from p to p2) makes no change, but each succeeding step gives a higher speed.

When the motor is stopped by opening the circuit, the springs 68 and 69 carry the arma ture 61 to its highest point, until the stop screws 87 87 strike the inner corners of pawls 73 73 and release their points from engagement in grooves 75, thereby allowing the plunger 76, plate 79, and cylinder 77 to be raised by springs 8l ready for the next operation ot the rheostat.

The diagrammatic illustration in Fig. 8 shows the main-liue circuits from the electriclight Iplug M. From this it will be seen that when contact is made with button against rod 2O ot' division H ot' the handpiece attachment G the local circuit from division E ol' the battery will be closed, energizing the magnets and 36 of main-circuit closer C and making contact through armature 37 to supply main-line current at 48. From this post current passes through the electromagn ets 59, 59, 60, and 60, after which it divides and forms a field-circuit and an armature-circuit. The former simply makes the circuit of the motor-field and returns to 49. rlhe latter passes through one side of the pole-changer (either to 48 or 50 to 49 when reversed) to contact. 85, thence top', 292,193,194, or p5, thence through more or less of the resistance F F' F2, thence through the armature ot' the motor, thence back through the other side of the pole-changer and main-circuit closer (49 to 5l) and to the plug M.

When the circuit of division H ot' the handpiece attachment G is closed, the main-line current will be sentthrough the motor, through the magnets of the rheostat B, and through all ot' the resistanccs F F' F2. As the magnets of the rheostat are energized their armature will be pulled down, causing contact 85 to engage contact p2; but as p and p2 are electrically connected the current will still pass through all ot' the resistances and no change ot' speed will occur. By opening and quickly closing the main-line circuit the armature of the rheostat will rise under action of its supporting-springs 68 69 and the pawls 73 engage a higher notch 75, when the quickly renergized magnets will pull the armature and plate 79 down, bringing contact 85 to contact p3, cuttingr out resistance F, and giving the next (increased) speed to the mo- Repetitions oi this opening and quickly ting ott' the main current, which, as before i closing ot' the main-line circuitwill bring con- IOO ITO

tact 85 successively in engagement with p4, cutting out resistance F', and p5, cutting out resistance F2, supplying the full strength of current to the motor and giving its highest speed.

From the foregoing it Will be seen that We have provided a complete, simple, and effective combination of appliances specially adapted for ready application to a surgicodental electric engine, although capable of use with other forms of electric engines or motors, whereby by simple manual or Finger action, Without changing the position of the handpiece or moving the hand therefrom, the operator is enabled to start, stop, reverse, or change the speed of the engine. The mainline circuit is not brought to ornear thehandpiece, our handpiece attachment being only connected up with the local-battery circuits, thus avoiding all danger of shocks to the operator or patient. All of the parts are of simple and economical construction and not liable to excessive Wear or damage with ordinary use.

Having thus fully described our invention, What We claim as new, and desire to secure by Letters Patent of the United States, is-

1. An electric engine provided with a handpiece and located in a main circuit, in combination with a main -circuit closer, a polechanger in the main circuit, and attachments to the handpiece for operating respectively, the main-circuit closer and pole-changer, substantially as described.

2. An electric engine provided with a handpiece, in combination `with a resistance-controller in the main circuit, and an attachment to the handpiece for operating the resistancecontroller, substantially as described.

3. An electric engine provided with a handpiece, in combination with a main-circuit closer, a resistance-controller in the main circuit and an attachment to the handpiece for operating the main-circuit closer and resistance-controller, substantially as described.

4. An electric engine provided With a handpiece, in combination with a pole-changer and a resistance-controllerin the main circuit,and attachments to the handpiece for operating the pole-changer and resistance-controller, respectively, substantially as described.

5. An electric engine provided with a handpiece, in combination with a main-circuit closer, a local current for operating the maincircuitcloser, and a circuit-closer for the local circuit attached to the handpiece, substantially as described.

0. An electric engine provided with a handpiece, in combination with a pole-changer, for the main circuit, a local current for operating the pole-changer, and a circuit-closer for the local circuit attached to the handpiece, substantially as described.

7. Au electric engine provided With a handpiece, in combination with a main-circuit closer, a pole-changer for the main circuit,

local circuits for operating the main-circuit closer and pole-changer respectively, and circuit-closers for said local circuits attached to the handpiece, substantially as described.

S. An electric engine provided with a handpiece, in combination with a main-circuit closer, a resistance-controller operated by the main-circuit closer, a local circuit for operating the main-circuit closer, and a circuitcloser for the local circuit attached to the handpiece, substantially as described.

9. An electric engine provided wi th a handpiece, in combination with a resistance-controller in the main circuit, a main-circuit closer for operating the resistance-controller, a pole-changer in the main circuit, local circuit for operating the main-circuit closer and pole-changer, and circuit-closers for the local circuits attached to the handpiece, substantially as described.

10. An electric engine provided with a polechanger, and a resistance-controller in the main circuit, a handpiece attachment for operating the resistance-controller, a local circuit for operating the pole-changer, and a circuit-closer for said local circuit attached to the handpiece, substantially as described.

11. An electric engine provided with a handpiece, in combination with a circuitcloser for the main circuit comprising electromagnets in a local circuit, an. armature therefor forming part of the main circuit When closed and a circuit-closer for the local circuit attached to the handpiece, substantially as described.

12. An electric engine provided with a handpiece,in combination With a pole-changer comprising electromagnets in a local circuit, an armature therefor forming part of the main circuit when closed, and a circuit-closer for the local circuit, attached to the handpiece, substantially as described.

13. An electric engine provided with a handpiece, in combination with a main-circuit closer comprising electromagnets in a local circuit, an armature therefor forming part of the main circuit when closed, a polechanger comprising electromagnets on another local circuit, an armature therefor forming part of the main circuit when closed, and circuit-closers for the local circuits attached to the handpiece, substantially as described.

14. An electric engine provided with a handpiece, in combination with a resistancecontroller comprising electromagncts connected up in the main circuit, an armature therefor for operating the resistance-controller, a main-circuit closer, a local circuit for operating the main-circuit closer, and a circuit-closer for the local circuit attached to the handpiece, substantially as described.

15. An electric engine provided with a handpiece, in combination with a series of resistances, a resistance-controller for bringing all or part of said resistances into the main circuit, a main-circuit closer Vfor oper- IOO ating the resistance-controller, and a handpiece attachment for operating the main-circuit closer, substantially as described.

16. An electric engine provided with a handpiece, in combination with a main-circuit closer, a pole-changer, a local batteryin two divisions connected together electrically, and with the main-circuit closer and polechanger, and a handpiece attachment for closing the circuit from one division of the battery through the main-circuit closer and from the other division ofthe battery through the pole-changer, substantially as described.

17. An electric engine provided with a handpiece, in combination with a main-circuit closer, a pole-changer in the main circuit, local circuits for operating the main-circuit closer and pole-changer, and a handpiece attachment comprising a push-button for closing the local circuit for the main-circuit closer, and a switch-lever for closing the local circuit for the pole-changer, substantially as described.

18. A handpiece attachment for an electric engine comprising a block of insulating material, means for clasping it upon the handpicce, and circuit-closing devices for a local circuit, substantiallfas described.

19. A handpiece attachment for an electric engine comprising a block of insulating material, means for clasping it upon the handpiece, and a plurality of circuit-@losers for local circuits, substantially as described.

20. A handpiece attachment for an electric engine comprising a block of insulating material, means for clasping it upon the handpiece, a longitudinal metal bar extending through the block, a metal rod connected to the bar and projecting from the top of the block, a switch-lever on saidy rod, and a curved rod extending from the end of the bar through it, and out of its top within contact of the switch-lever, substantially as described.

2l. A handpiece attachment for an electric engine, comprising'a block of insulating material, means for attaching it to the handpiece, a longitudinal metal bar extending through the block, a metal rodconnected to the bar and projecting from the top of the block, a switch-lever on the rod, a contact bar for the switch-lever extending through the end of the block, a parallel longitudinal bar in the block, and a push-button for electrically connecting the two longitudinal bars, substantially as described.

22. A main-circuit closer, for an electric engine comprising oppositely-located pairs of binding-posts in the main circuit, pins electrically connected with the respective binding-posts of the pairs, electromagnets in a local circuit, an armature therefor adapted to contact with the pins when the local circuit is closed, plates in the main circuit, and contact-pins on the armature engaging said plates, substantially as described.

23. A main-circuit closer for an electric engine comprising electromagnets 35, 36 in a local circuit, the pivoted armature 37, the platinum-faced blocks 39, 40 projecting from said armature, the pins 41, 42 on the positive and negative sides of the main circuit, the plates 45, 46 in the negative and positive sides of the main circuit, and the pins 43 and 44 passing through the armature and blocks 39, 40 and contacting with said plates, substantially as described.

24. A resistance-controller for an electric engine comprising electromagnets in the main circuit, an armature therefor normally held away from the magnets, a pneumatic cylinder, a plunger therein normally held raised, a contact-point carried by anda series of notches in said plunger, a series of stationary contact-points adjacent to the plunger, and pawls carried by the armature and engaging the notches of the plunger, substantially as described.

25. A resistance-controller for an electric engine comprising electromagnets connected up in series in the main circuit, an armature normally held away from the magnets, apneumatic cylinder, a plunger therein normally held raised, a contact-point in the main circuit carried by and a series of notches in said plunger, a series of stationary contact-points adjacent to the plunger and connected up with resistances, pawls carried by the armature and engaging the notches of the plunger, and means for admitting and discharging air from the pneumatic cylinder, substantially as described.

HENRI LETORD. JOSEPH S. LETORD. Witnesses:

J. N. McELRoY, JAMES G. SMITH.

IOO 

